Impact of Dose-Volume Parameters of Parotid Glands on Xerostomia in Patients Irradiated for Head-and-Neck Cancer.

BACKGROUND/AIM: Optimal planning of radiotherapy for head-and-neck cancers should consider the risk of xerostomia. This study investigated the prognostic value of dosevolume parameters of the parotid glands. PATIENTS AND METHODS: Dose-volume parameters were evaluated for xerostomia in 145 patients including D40 (minimum dose to 40% of corresponding parotid volume), D60 (minimum dose to 60%), D80 (minimum dose to 80%), and mean dose of ipsilateral, contralateral, and bilateral parotid glands. RESULTS: Grade ≥2 xerostomia was significantly associated with D40 of ipsilateral and all parameters of bilateral glands; trends were found for all other parameters. Grade ≥3 xerostomia was significantly associated with D80 of bilateral glands; trends were found for other parameters of ipsilateral and bilateral glands. CONCLUSION: Since grade ≥2 xerostomia was associated with all parameters, D40, D60, and D80 did not provide additional information to mean doses. D80 of bilateral glands is a new factor and more predictive than mean dose regarding grade ≥3 xerostomia.

Prognostic Factors for Complete Recovery From Xerostomia After Radiotherapy of Head-and-Neck Cancers.

BACKGROUND/AIM: Radiotherapy of head-and-neck cancers can cause xerostomia. This study investigated potential prognostic factors for complete recovery from this complication. PATIENTS AND METHODS: Eighty head-and-neck cancer patients with radiation-induced xerostomia were retrospectively evaluated. Thirteen characteristics were analyzed for complete recovery (to grade 0) from xerostomia including age, sex, tumor site and stage, nodal stage, upfront surgery, mean dose to ipsilateral, contralateral and both parotid glands, chemotherapy, radiation type and dose, and initial grade of xerostomia. RESULTS: Fifteen patients (18.8%) experienced complete recovery of xerostomia. Significant associations with complete recovery were found for initial grade 1 xerostomia (p<0.001), mean dose to contralateral parotid gland of <20 Gy (p=0.034), and radiation treatment without chemotherapy (p=0.047). CONCLUSION: Almost every fifth patient experienced complete recovery of xerostomia. Prognostic factors were identified that can guide radiation oncologists during the process of treatment planning.

The First Prognostic Tool to Estimate the Risk of Late Grade ≥3 Xerostomia in Patients Irradiated for Head-and-Neck Cancer.

BACKGROUND/AIM: Xerostomia is a serious complication following radiotherapy of head-and-neck cancers. A prognostic tool was developed for estimating its risk. PATIENTS AND METHODS: In our previous study, age, tumor site, bilateral lymph node involvement, definitive radiotherapy, and addition of systemic therapies showed significant associations with grade ≥3 late xerostomia or trends. In additional analyses, mean radiation dose to ipsilateral parotid gland was significant (p=0.011). These six factors were included in the prognostic tool. Scoring points of 0 (lower risk) or 1 (higher risk) were assigned to each factor and added for each patient. RESULTS: Patient scores ranged between 0 and 6; Grade ≥3 xerostomia rates were 0%, 8%, 24%, 26%, 25%, 42%, and 100%, respectively. Three groups were designed (0-1, 2-4, and 5-6 points) with grade ≥3 xerostomia rates of 5%, 25%, and 50%, respectively (p<0.001). CONCLUSION: This new tool helps estimating the risk of radiation-induced grade ≥3 xerostomia. It can support physicians and other medical staff members during treatment planning.

Risk Factors for Xerostomia Following Radiotherapy of Head-and-Neck Cancers.

BACKGROUND/AIM: Many head-and-neck cancer patients receive radiotherapy, which may be associated with significant toxicities. Xerostomia is considered one of the most debilitating late adverse events. This study was performed to identify risk factors for xerostomia. PATIENTS AND METHODS: Several characteristics were investigated for associations with late xerostomia in 159 patients irradiated for head-and-neck cancer including age, sex, tumor site and size, underlying pathology, histologic grading, upfront resection, systemic treatment, and type and dose of radiotherapy. RESULTS: Ninety (57%) and 35 (22%) patients experienced grade ≥2 and ≥3 xerostomia, respectively. Grade ≥2 xerostomia was significantly associated with tumor site (nasopharynx/oropharynx/oral cavity/floor of mouth, p=0.049). Grade ≥3 xerostomia was significantly associated with age ≥61 years (p=0.035); trends were found for tumor site (p=0.088), bilateral nodal involvement (p=0.093), definitive treatment (p=0.082), and systemic treatment (p=0.055). CONCLUSION: Risk factors for xerostomia following radiotherapy of head-and-neck cancers were identified including older age, unfavorable tumor site, bilateral involvement of lymph nodes, definitive treatment, and addition of systemic therapies. For patients with risk factors, sparing of the salivary glands is particularly important.